Synthesis of 1 H-Pyrrol-3(2 H)-ones via Three-Component Reactions of 2,3-Diketo Esters, Amines, and Ketones

Multicomponent Cyclizative 1,2-Rearrangement Enabled Enantioselective Construction of 2,2-Disubstituted Pyrrolinones

The 1,2-rearrangement reaction is one of the most important approaches to construct carbon-carbon bonds in organic synthesis. However, the development of catalytic asymmetric 1,2-rearrangements is still far from mature and often suffers from problems such as complex substrates, single product structure, and lack of synthetic application. Multicomponent reaction has been recognized as a robust tool for the synthesis of diverse and tunable products from readily available starting material. Conceptionally and practically, the development of multicomponent asymmetric 1,2-rearrangements is highly desirable. In this regard, we report herein a three-component benzilic acid-type rearrangement of 2,3-diketoesters, aromatic amines and aldehydes for the asymmetric construction of synthetically challenging pyrrolinones bearing aza-quaternary stereocenters. To the best of our knowledge, this reaction represents the first example of organocatalyzed multicomponent asymmetric 1,2-rearrangements.

Polyfunctionalization of vicinal carbon centers and synthesis of unsymmetric 1,2,3,4-tetracarbonyl compounds

The synthesis and characterization of organic compounds with unusual atom or functional group connectivity is one of the main driving forces in the discovery of new synthetic methods that has raised the interest of chemists for many years. Polycarbonyl compounds are such compounds wherein multiple carbonyl groups are directly juxtaposed and influence each other's chemical reactivity. While 1,2-dicarbonyl or 1,2,3-tricarbonyl compounds are well-known in organic chemistry, the 1,2,3,4-tetracarbonyl motif remains barely explored. Herein, we report on the synthesis of such 1,2,3,4-tetracarbonyl compounds employing a synthetic strategy that involves C-nitrosation of enoldiazoacetates, while the diazo functional group remains untouched. This strategy not only leverages the synthesis of 1,2,3,4-tetracarbonyl compounds to an unprecedented level, it also accomplishes the synthesis of 1,2,3,4-tetracarbonyl compounds, wherein each carbonyl group is orthogonally masked. Combined experimental and theoretical studies provide an understanding of the reaction mechanism and rationalize the formation of such 1,2,3,4-tetracarbonyl compounds.

Cu(I)-Catalyzed [2 + 2 + 1] Cycloaddition of Amines, Alkynes, and Ketenes: An Umpolung and Regioselective Approach to Full-Substituted β-Pyrrolinones

Described here is a Cu-catalyzed [2 + 2 + 1] modular synthesis of full-substituted β-pyrrolinones from simple amines, alkynes, and α-diazo-β-ketoesters. This approach involving the regioselective C-nucleophilic attack of enamines, uncommon C-nucleophilic addition to ketenes, and umpolung of imines enables the direct synthesis of full-substituted β-pyrrolinones, which were hardly constructed by traditional synthetic strategies.

Facile synthesis of penta-substituted pyrroles and pyrrole-fused piperidin-4-ones via four component reactions of 2,3-diketoesters, anilines and enaminones

Novel and facile multicomponent reactions of 2,3-diketoesters, anilines and enaminones were developed. A variety of penta-substituted pyrroles and pyrrole-fused piperidin-4-ones can be easily accessed via interception of cationic intermediates.

Recent applications of ninhydrin in multicomponent reactions

Ninhydrin (1,2,3-indanetrione hydrate) has a remarkable breadth in different fields, including organic chemistry, biochemistry, analytical chemistry and the forensic sciences. For the past several years, it has been considered an important building block in organic synthesis. Therefore, there is increasing interest in ninhydrin-based multicomponent reactions to rapidly build versatile scaffolds. Most of the works described here are simple reactions with readily available starting materials that result in complex molecular architectures. Some of the synthesized compounds exhibit interesting biological activities and constitute a new hope for anticancer agents. The present review aims to highlight the multicomponent reactions of ninhydrin towards diverse organic molecules during the period from 2014 to 2019.

This article aims to review recent multicomponent reactions of ninhydrin towards diverse organic scaffolds, such as indeno-fused heterocycles, spiro-indeno heterocycles, quinoxalines, propellanes, cage-like compounds, and dispiro heterocycles.